Identify what tests to order prior to referral to Rheum for RA
- RF, anti-CCP, ANA, ESR/CRP, Xray of hand/wrist (feet if involved), CBCD, LFT’s, Chronic Hep Panel, Creatinine (in case MTX started), Quantiferon (to rule out TB prior to possible start of biologic agents).

Evaluating for Rheumatoid Arthritis in Family Medicine Clinic
By Anni Hansen, MD
Sources: Current Diagnosis and Treatment: Rheumatology, Second Edition (Imboden, Hellmann and Stone)
Dynamed- Rheumatoid Arthritis, UpToDate Rheumatoid Arthrits



Rheumatoid arthritis
Osteoarthritis
Who gets it?
RA can present in any age in any patient but more common in women (3:1). Typical onset in women in late childbearing years, men often have onset in 6th to 8th decade.
Prevalence approximately 1%
Increasing prevalence with age. Women tend to have earlier onset of OA in hands and knees than men. Other risk factors include joint injury and obesity.
Which joints are usually involved?
Symmetric small joints (MCP, PIP and MTP) but spares DIP.
Can involve almost all synovial joints including wrists, elbows and ankles, shoulders, knees. Usually symmetric on both sides of body and larger joints generally involved later in the course of the disease.
Can involve C1-C2 articulation.
OA in hands usually DIP (Heberden’s nodules), PIP (Bouchard’s nodules) and 1st MCP (base of thumb).
Neck, spine, hips and knees, 1st MTP.
Symptoms:
Joint stiffness worse in morning, pain, swelling on exam, warmth of joints
Joint pain that increases with activity, crepitus, bony enlargement at joint margin, tenderness to palpation over the joint.
- Morning stiffness
Usually greater than 1 hour to get “as good as you are going to get”
Usually brief and self limited
Systemic symptoms
Fatigue, possible weight loss, occasional low-grade fevers
Absence of prominent constitutional symptoms
Labs:
Elevated ESR or CRP or both
Anemia of chronic disease
Thrombocytosis is common
Anti-CCP elevated (present in 60-70% of patients with RA at diagnosis and is 90-98% specific, it strongly correlates with erosive disease)
RF positive in 50% of cases at presentation and an additional 20-35% become positive in 1st 6 months after diagnosis. RF is not specific and can be elevated in RA, sjogren, SLE, viral infections (Hep C, EBV, parvovirus, influenza), endocarditis, osteomyelitis, chronic inflammatory conditions, liver disease, inflammatory bowel disease, aging.
ESR in normal range for age
Negative serologic tests
Synovial fluid
Inflammatory synovial fluid with WBC between 5000-50,000/mm3, 2/3 neutrophils
Non-inflammatory synovial fluid with <1000WBC/mm3
Xray findings
Bony erosions, symmetric loss of cartilage space, periarticular osteopenia
Joint space narrowing, osteophytes, subchondral cysts and bony scerosis
Differential Diagnosis of Rheumatoid Arthritis:
- Acute viral syndromes (Hep B, Hep C, parvovirus, Rubella, EBV) can produce polyarthritis that mimics EBV but usually resolve after 2-4 weeks.
- Systemic Lupus. To help rule this out ask about rashes, oral ulcers, renal and pulmonary problems, history of blood clots or miscarriages. Check an ANA.
- Psoriatic Arthritis- Ask about history of psoriasis, nail changes (pitting), dactylitis (sausage digit).
- Reactive arthritis- Ask about urethritis, GI infections. Usually involves axial skeleton and is an inflammatory oligoarthritis if peripheral joints. Can have enthesitis (inflammation at insertion of tendons, ligaments and fascia to bone).
- Gout and pseudogout
- Infectious arthritis
- Sarcoidosis, other connective tissue diseases (Sjogren’s, overlap syndrome) Lyme disease, rheumatic fever, paraneoplastic disease (myelodysplasia, hypertrophic pulmonary osteoarthropathy) etc

Testing to consider if you suspect RA:
- Labs: CBCD, CRP, ESR, RF, anti-CCP, LFTs, Chronic hepatitis panel, creatinine, UA, if concerned regarding possible lupus check ANA, stool fecal occult blood.
- Xrays of effect joints.
- If will be starting a biological disease modifying agent check a PPD or Quantiferon.

Patients with suspected RA should be referred to a rheumatologist urgently. If they are anti-CCP positive it is important to start disease modifying agents within 3 months of diagnosis to prevent further erosions.

Prednisone (short term) and NSAIDs can be used in combination with DMARDs.

Treatments (should be actively managed by a rheumatologist):
Disease Modifying Agents (DMARDs):
- Methotrexate. Must rule out hepatitis or liver disease prior to starting. Women of child bearing age must be on effective birth control and be counseled in Class X status of drug. It is given once per week (5-25mg) to be taken with daily folic acid. Monitor LFTs, CBCD and Creatinine every 1-3 months
- Hydroxychloroquine. Safe and good to use in combination with other medicines. Should get ophthalmology checks.
- Sulfasalazine. Monitor white blood cells in 1st 6months. Titrate up slowly to avoid GI side effects.
- Minocycline. Long term therapy can cause hyperpigmentation.
- Leflunomide (Arava). Teratogenic with long half-life. Blood levels should be checked prior to pregnancy even if therapy was years ago. Monitor CBCD and LFTs.

Biological DMARDs: Must rule out latent TB prior to starting. Increases risk of infections such as cellulitis, septic joints, TB, histoplasmosis, coccidioidomycosis and Listeria.

- Etanercept (Enbrel). Injected twice weekly. TNF inhibitor.
- Adalimumab (Humara). Injected every other week. TNF inhibitor.
- Infliximab (Remicade). Infusion every 4-8 weeks. TNF inhibitor.
- Anakinra. Daily injections, slower onset. Less commonly used. IL-1 antagonist.
- Abatacept (Orencia). Selective T cell modulator. Can work on patients who have active disease refractory to TNF inhibitor.
- Rituximab (Rituxan). Antibody against CD20 molecule.






This page has been edited 2 times. The last modification was made by - mwong04 mwong04 on Mar 21, 2011 11:58 am